Conventionally, the activity of a bulk radiation waste is measurement by the use of a container-style detection system that is located at a fixed place. However, the container-style detection system is generally composed of a plurality of scintillator detectors that can be very costly to establish. In addition, since the area in the container-style detection system for housing objects to be detected is limited, the detected object that is too large has to be divided and kept separately in barrels or boxes for preparing the same to be carried in batch to the container-style detection system for measurement. Moreover, the container-style detection system can only be used for measuring radiation specific activity (Bq/kg) and is not capable of identifying radionuclides. Therefore, the radiation measurement methods that are currently available are not easy and convention to apply for decommissioning a nuclear facility in real world, not to mention that a permanent site must be provided and acquired in advance for the container-style detection system.